Furnace wall



O. NYGAARD Feb. 27, 1934'.

FURNACE WALL Filed Dec. 30, 1931 4 Sheets-Sheet l ATTURNE I 0. NYGAARDFeb. 27, 1934.

FURNACE WALL 4 Sheets-Sheet 2 Filed Dec. 30; 1931 Feb. 27, 1934.

o. NYGAARD FURNACE WALL 4 Sheets-Sheet 3 Filed Dec.

iqATTgR/VEM nlil o. NYGAARD 1,948,798

FURNACE WALL Filed Dec. 30. 1951 4 Sheet-Sheet -4 IN I/E N TOE PatentedFeb. 27, 1934 4 FURNACE WALL Oscar Nygaard, Saugus, Mass.

Application December 30, 1931 Serial No. 583,835

24 Claims. (01. 72-101) This invention relates to furnace walls.

In my copending application Serial No. 425,448, filed February 3, 1930,I have shown a sectional steel supported wall which represents asubstantial advance in this art. The present invention is especially,but not exclusively, concerned with walls of this general type. It aimsto improve such walls with a view to facilitating the erection of thewalls, reducing the weight of the structural metal, and more especiallythe castings used in walls of this general type, and devising a wallstructure which can readily be adapted to the requirements of a widevariety of installations. Some features of the invention may also beused to advantage in other types of walls.

The natureof the invention will be readily understood fromthe followingdescription when read in connection with the accompanying drawings, andthe novel features will be particularly pointed out in the appendedclaims.

In the drawings, I

Figure 1 is a perspective view, partly in section, of a partly erectedwall embodying this invention;

Fig. 2 is a vertical, sectional view of a portion of the wall shown inFig. 1;

Fig. 3-is a horizontal sectional viewof a part of said wall;

Fig. 4 is a plan view of a modified form of bar for holding certain ofthe refractory blocks in place;

. Figs. 5 and 6 are plan and vertical sectional views, respectively, ofanother bar construction for holding the blocks in position;

Figs. 7 and 8 areyertical' and horizontal sectional views, respectively,of another modifica tion; and v 2 Figs. 9 and 10 are similar views ofstill another embodiment of the invention.

Referring first to Figs. 1, 2 and 3, the wall structure there showncomprises a front section A, a rear section B, and an intermediate airspace C separating saidfront and rear sections. The wall includes astructural steel frame, the particular design of which necessarily willvary somewhat with the requirements of diiferent installations. In theillustrated construction this frame includes a series of upright posts 2at the back of the wall, another series of upright posts Slocated at anintermediate point in the wall, all of these posts being of T-shape intransverse section, horizontal'beams 4 bolted, riveted, or welded to theposts 2, additional beams 5 similarly connected to the posts 3, and'cross pieces 6 which are bolted, riveted or welded to the\adjacentflanges of the opposed posts 2 and 3, and

= which secure the front and rear sections of 'the,

frame rigidly to each other. The rear wall section also includes coursesof brick 8 and frequently, also,'other heat insulating materials whichmay serve both to close the back of the wall, andalso to prevent anygreat degree of heat loss at the back of the wall.

The front wall section or lining is exposed to the heat generated in thecombustion chamber. It must'be expected, therefore, that the bricks orblocks used at this point in the wall will require replacement after areasonable length of time, and the present invention makes provision forsuch renewal of the lining and for the repair of small individualsections of the lining in the event that blocks become broken. Partlyfor these reasons the lining is madeup of sections or panels whichlareseparated from each other by expansion joints.

In the construction shown in Figs. 1 and 2, the lining is composedchiefly of blocks 10 which may be made of fire clay, silicon carbide, orother suitable refractory materials, silicon carbide ordinarily beingpreferred. The construction of an individual panel will be clear from aninspection of Figs. 1, 2 and 3, it being observed that the lowermost rowof blocks 10 in the panel shown .in Fig. 2 rests directly'on ahorizontal beam 12 which is bolted to two adjacent posts This beam isconstructed to support a relatively heavy weight and it is provided'onits upper side with a upwardly extending flange or lip 13 which ente s agroove 14 formed in the lower face of each of the blocks 10. Acorresponding groove 15 is formed in the upper face of each of theseblocks. Fitting in the latter groove is the end flange of a T-b r 16,the construction of which will be clearly nderstood from an inspectionof the drawings. This bar fits between two adjacent posts 3-,3 and isslotted at its opposite ends to receive the upright flanges of saidposts so that the bar can slide freely up and down on said flanges, Itcan bev placed in position between two adjacent posts by tipping it intoa diagonal or inclined -position, inserting first one flange and thenthe other in the respective slots and then swinging the bar into ahorizontal position as shown, for example, in Fig. 1. The panel shown inFig. 2 includes three horizontal rows of blocks 10, the blocks in theindividual rows being indicated at 10, 10 and 10. The weight of theentire panel is supported on the beam 12, each of the upper rows ofblocks resting directly on the row under it. The bars 16, however, serveto hold the upper rows of blocks in alinement in the front section ofthe wall due to the interlocking engagement of the flange of each barwith the blocks immediately above and below it, and also due to theconnection of said bar with the posts 3-3. It is preferable, althoughnot necessary, to tongue and groove the blocks, as shown in Figs. 1 and2, in order to assist further in alining them with each other. At thetop of each panel is a course or row of key blocks 1O which are notengaged by the bars 16 but are held in position by their tongue andgroove connection with the blocks 10 and also by the packing 17 in theexpansion joint which separates this panel from the next panel above it.

All of the panels preferably are constructed in the manner justdescribed, each being substantially a duplicate of the other. Adjacentpanels are separated vertically by horizontal expansion joints 1'? andare separated laterally by vertical expansion joints 18, each of thelatter joints including a packing 19, Figs. 1 and 3, of asbestos,magnesium, or other refractory material, mixed with a refractory cementand located chiefiy in a groove formed in the blocks at the right-handedge of the panel. The packing used in both the horizontal and verticalexpansion joints should be of a fibrous and-yielding nature so that itwill effectually close the joints against any undesirable leakage of airor gas through the front section of the wall from the air space c to thecombustion chamber, or vice versa, while still permitting expansion andcontraction of the panels relatively to each other due to changes .intemperature.

In installing the wall the steel frame is first erected. Certain of thebeams 12 for supporting the panels are then secured in position, and theindividual panels then are assembled. In this operation the bottom row10 of blocks is first placed on the beam 12 for that particular panel, abar 16 next is placed in position with its flange in the grooves of theblocks 10*, the next row of blocks 10 then is placed on the first row,and the operations just described are repeated, the key blocks 10 beingfinally placed in position. The packings 17 and 19 for each panel areput in place before the assembly of vided at one end with a plate 20pivoted to the bar by means of a bolt 21. This plate may be looselyfastened to the bar, the bar placed properly on top of the row of blockswhich it is to lock in place, and the plate 20 may then be swung intoposition behind the flange of the post,3 and secured in that position bytightening up the nut on the bolt 21.

In some cases it may be desirable to be t, rivet, or weld horizontalangle bars 22 to the po ts 3, as shown in Figs. 5 and 6, and to use T-bars 24 instead of the bars 16 to hold the blocks.J,9 in place, each ofthese T-bars having an end 25 to hook over one of the angle bars 22.

A further modification is shown in Figs. 7 and 8 in which the refractoryblocks 10 are cut away at their opposite sides, as best shown in Fig. 8,to provide air passages 2'7, extending inwardly from the air space Cbetween the front and rear wall sections to points adjacent to the fireface of the wall. While ordinarily the blocks in the lining are arrangedin staggered relationship, as shown in Fig. 1, this arrangement is notnecessary and the blocks may be located in vertical alinement with eachother so that the air spaces 27 provided between adjacent blocks in onerow will line up and register with those in the rows above and below it.Such an arrangement is of advantage in those constructions in which itis desirable to increase the rate of heat transfer from the lining. Insuch cases usually a forced draft is created through the air space C bymeans of a blower and. the air so preheated may be used for combustionpurposes, for drying coal, or in any other desired manner.

If a greater cooling effect is desired at points closely adjacent to thefire face of the wall, the arrangement shown in Figs. 9 and 10 mayconveniently be used. In this construction the blocks 10" are reduced attheir opposite sides to provide air passages 28 which open into ahorizontal passage 30 extending parallel to the fire face of the wall,the forward portions of the blocks 10 being cut away to form thispassage. In this case each block carries a removable facing brick 31which completely covers the front face of the block, these bricks beingmade of silicon carbide, or some other highly refractory material, whilethe blocks are made of fire clay or the like. As shown in Fig. 9 eachblock 10 is notched at its upper edge and the facing brick 31 for it isprovided with a hook which fits into said notch, each facing brick thusbeing hooked on to its respective supporting block 10'. The bricks mayfit closely against each other laterally but a clearance space isprovided between adjacent rows of these facing bricks, as shown in Fig.9, so that each row may expand vertically Without interfering with thenext adjacent row. Lateral expansion of each row of facing bricks ispermitted due to the presence of the vertical expension joints 18. Thearrangement shown at the right of Fig. 10 is like that shown at the leftof said figure except that each facing brick 30' is shaped to fit on andprotect the forward sides of two adjacent blocks 10" and is madeslightly narrower than the two blocks and not quite as high as theindividual blocks so that each brick can expand freely both verticallyand laterally. In such an arrangement if an air pressure is maintainedin the air space C some air will escape through the front section of thewall into the combustion chamber. This arrangement, therefore, issuitable chiefly for those installations in which it is desired to haveair introduced in this manner. No facing brick supports the weight ofanyother brick.

In these constructions, strips 32, Fig. 10, of refractory material areplaced in front of each of the posts 3 both for the purpose of blocking\the escape of air or gases through the expansion joints l8 and moreparticularly to protect the structural steel members from the action ofthe hot gases in the combustion chamber.

Key blocks 33, Fig. 9, may be used with the blocks 10" in essentiallythe manner above described in connection with Fig. 2, and a facing brick34 may be associated with each key block or filler block but located ina reverse relationship to it from that occupied by the other facingbricks with reference to their respective blocks. A refractory packing17' closes the till space between the row of key blocks or filler blocksand the next panel above it.

When it becomes necessary to renew a panel of the wall shown in Figs. 1and 2, or to replace a broken brick, the packing is dug out of theexpansion joint immediately above that individual panel, the key blocks10* for that panel are removed and as many of the other blocks 10 aretaken out as may be necessary to get down to the broken block. Thedesired number of new blocks are then placed in position, the other rowsof blocks are replaced, and the expansion joint is filled with packingmaterial. The fact that the bars 16 are readily removable facilitatesthis operation since each bar must be taken out, or at least lifted,before the row of blocks with which it is interlocked can be removed.The wall constructions shown in Figs. '7 and 9 can be repaired insubstantially the same manner.

The invention thus provides a furnace wall of the structural steelsupported type in which a relatively small weight of metal is requiredand in. which the erecting and repairing operations can be performedvery easily and economically. The construction also lends itself readilyto the minor modifications required to adapt it to the peculiarities ofindividual installations. It will be observed that the .opposed frontand rear posts 3 and 2, respectively, are connected together by crosspieces in such a manner as to form an upright open truss. Thisconstruction is of particular advantage when a positive circulation ofair is to be maintained through the air space in the front and rear wallsections, either for the purposes of cooling the front section orpreheating the air, or both, since it permits a free circulation bothvertically and horizontally. At the same time the flow of air can becontrolled by baffles inserted at any. desired poinm and secured to theframe. Horizontal baffles are shown, for example, in Fig. l. The airspace 0 also is of advantage in insulating the rear wall section fromthe front section and thus reducing the transfer of heat to the extremerear surface of the wall. In the arrangement shown in Figs. 1, 2 and 3the structural steel posts 3 are protected from the heat of thecombustion chamber both by the inner wall or lining and also by the airspace between the posts and the lining.

In the wall construction shown in Figs. '7 to 10, in-

clusive, the posts 3 have been set into the front wall section in orderto reduce the overall thickness of the wall and here these members areprotected by slabs or strips 32 of. asbestos or other refractorymaterial. It is extremely important that the steel members be adequatelyprotected, in these wall constructions since they would deteriorate veryrapidly if exposed to too high a temperature.

While I have herein shown and described convenient embodiments of myinvention, it will be understood that the invention may be embodied inother forms without departing from the spirit or scope thereof.

Having thus described my invention, what I desire to claim as new is:

1. A furnace wall comprising a permanent rear wall section, a structuralsteel frame in said wall comprising posts located in an intermediateposition in the wall and including a horizontal beam secured rigidly tocertain of said posts, a horizontal row of refractory blocks resting onsaid beam and forming a part of the lining for said wall, anotherhorizontal row of lining blocks resting on the first mentioned row, anda bar .releasably connected with said frame for holding said additionalrow of blocks in their operative positions.

2. A furnace wall comprising a permanent rear wall section, a structuralsteel frame in said wall comprising'posts located in an intermediateposition in the wall and including a horizontal beam secured rigidly tocertain of said posts, a horizontal row of refractory blocks resting onsaid beam and forming a part of the lining for said wall, anotherhorizontal row of lining blocks resting on the first mentioned row, anda bar slidable vertically on the latter posts and operative to hold saidadditional row of blocks in their operative positions.

3. A furnace wall comprising a permanent rear wall section, a structuralsteel frame in said wall comprising posts located in an intermediateposition in the wall, a removable lining positioned in front of andspaced from said rear wall section and comprising a plurality of panelseach including horizontal rows of refractory bricks positioned one aboveanother, a plurality of horizontal beams secured to said posts andsupporting, respectively, the bottom. rows of blocks in said panels, andhorizontal bars removably mounted on said frame and interlocked withsaid upper rows of blocks to hold the latter blocks in their operativepositions in said lining.

4. A furnace wall comprising a permanent rear wall section, a structuralsteel frame in said wall comprising posts located in an intermediateposition in the wall, a removable lining positioned in front of andspaced from said rear wall section and comprising a plurality of panelseach including horizontal rows of refractory bricks positioned one aboveanother, a plurality of horizontal beams secured to said posts andsupporting, respectively, the bottom rows of blocks in said panels, andhorizontal bars mounted for vertical slidable movement on said posts andengaged with said upper rows of blocks to hold them in their operativepositions in said lining.

5. A furnace Wall comprising a permanent rear wall section, a structuralsteel frame in said well comprising posts located in an intermediateposition in the wall, a removable lining positioned in front of andspaced from said rear wall section, said lining comprising a pluralityof panels each including a plurality of horizontal rows of refractoryblocks, said rows in each panel being positioned one above another, ahorizontal beam secured rigidly to certain of said posts and supportingthe bottom row of blocks in one of said panels, a horizontal barreleasably connected with said frame and including a flange lyingbetween and interlocked with two superposed rows of blocks in the latterpanel, said bar serving to hold the blocks which it engages in theiralined positions in said lining, and similar beams and bars cooperatingin the same manner with the blocks of the other panels.

6. A furnace wall according to preceding claim 5 in which said panelsare separated from each other by expansion joints which are packed topermit relative expansion and contraction of the panels without openingthe joints, each panel also including a row of key blocks which areremovable from the wall at the fire side thereof, said supporting meansfor the other blocks of each panel being arranged to permit the removalof the latter blocks of any panel, after the key bricks have beenremoved, without disturbing either the adjacent panels or the rear wallsection.

7. A furnace wall comprising front and rear wall sections with an airspace separating said sections, a structural steel frame in said wallfor supporting said sections, said front section including horizontalrows of blocks arranged one above another, and said front section havingpassages extending thereinto from said air space and terminating atpoints adjacent to the fire face of said wall, through which passagesand air space a free circulation of air can be maintained.

8. A furnace wall.comprising front and rear wall sections with an airspace separating said sections, a structural steel frame in said wallfor supporting said sections, said front section including horizontalrows of blocks arranged one above another, and horizontal bars engagingsaid blocks and cooperating with said frame to hold said blocks properlyalined in the wall, said front section having air passages extendingthereinto and permitting a circulation of air from said air space topoints adjacent to the fire face of the wall.

9. A furnace wall comprising front and rear wall sections with an airspace separating said sections, a structural steel frame in said wallfor supporting said sections, said front section including horizontalrows of blocks arranged one above another, horizontal bars interlockedwith said blocks and holding the blocks properly alined in the wall,said blocks having air.passages between them opening into said air spaceand extending toward the fire face of said front section but terminatingat points adjacent to said face.

10. A furnace wall comprising front and rear wall sections with an airspace separating said sections, a structural steel frame in said wallfor supporting said sections, said frame including upright open trussesthrough which a horizontal circulation of air through said air space canbe maintained, said front section including horizontal rows of blocksarranged one above another, and means carried by said frame for holdingsaid blocks in their normal positions in the wall, said front sectionhaving air passages extending thereinto from said air space andterminating at points adjacent to the fire face of the wall, throughwhich air passages and air space a free circulation of air can bemaintained.

11. A furnace wall according to preceding claim 3 in which said liningis provided with air passages located behind but terminating adjacent tothe fire face of said front wall section and in free communication withsaid air space between said front and rear wall sections.

12. A furnace wall comprising front and rear wall sections with an airspace between them, said front section including blocks supported forremoval from the wall at the fire side thereof without disturbing saidrear wall section and refractory facing bricks supported on said blocks,said front section having an air passage therein lying parallel to thefire face of the wall and located immediately behind said bricks, saidpassage extending continuously past several of said bricks and beingconnected by additional passages with said air space.

13. A furnace wall comprising a permanent rear wall section, a renewablelining located in front of said rear wall section and comprising aplurality of rows of refractory blocks positioned one above another, astructural steel frame in said wall including posts embedded in saidlining and carrying at least a part of the weight of the lining, 'saidposts being protected by said blocks from the heat generated inthecombustion chamber, and additional insulating material protectingsaid posts from the heat of the combustion chamber.

14. A furnace wall comprising front and rear wall sections with an airspace separating said sections, a structural steel frame in said wallfor supporting said sections, said front section including horizontalrows of blocks arranged one above another, means cooperating with saidframe for supporting said blocks in their operative positions butpermitting the disengagement of the blocks from their supporting meansand the removal of the blocks from the wall at the fire side thereofwithout disturbing said rear wall section, said front section having anair passage therein lying parallel to the fire face of the wall butlocated behind said fire face and extending across a series of saidblocks, said front section also being provided with air ducts connectingsaid passage with said air space.

15. A furnace wall comprising front and rear wall sections with an airspace separating said sections, a structural steel frame in said wallfor supporting said sections, said front section including horizontalrows of blocks arranged one above another, means cooperating with saidframe for supporting said blocks in their operative positions butpermitting the disengagement of the blocks from their supporting meansand the removal of the blocks from the wall at the fire side thereofwithout disturbing said rear wall section, facing bricks of highlyrefractory material removably supported on said blocks at the fire sideof the wall, said front wall section having an air passage thereinlocated immediately behind said facing blocks and extending parallel tothe fire face of the wall and connected with said air space by airducts, whereby a circulation of air can be maintained through saidpassages and ducts in contact with the rearward surfaces of said facingbricks.

16. A furnace wall comprising front and rear wall sections with an airspace separating said sections, a structural steel frame in said wallfor supporting said sections, said front section including horizontalrows of blocks arranged one above another, means carried by said framefor supporting said blocks in their operative positions with said blocksdisengageable from their said supporting means and removable from thewall at the fire side thereof without disturbing said rear wall section,said-front section being provided with air passages extending thereintofrom said air space and terminating at points adjacent to the fire faceof the wall.

' 1'7. A furnace wall comprising front and rear wall sections with anair space between them, said front section including rows of blocks,means supporting said blocks for removal from the wall at the fire sideof the wall without disturbing said rear wall section, and refractoryfacing bricks removably supported on said blocks at the fire side of thewall, said front wall section having air passages leading thereinto fromsaid air space to the rear surfaces of said facing bricks.

18. A furnace wall comprising front and rear wall sections with anair-space between them,

said front section including rows of blocks, means lar bricks by asufficient distance to permit the vertical expansion of onerow'independently of the next adjacent row.

19. A furnace wall comprising front and rear wall sections with an airspace between them, said front section including rows of blocks, meanssupporting said blocks for removal from the wall at the fire side of thewall without disturbing said rear wall section, and refractory facingbricks removably supported on said blocks at the fire side of the wall,said facing bricks being arranged in panels separated from each other byexpansion joints, and adjacent rows of said bricks being spaced apart bya sufficient distance to permit them to expand and contractindependently of each other. I

20. A furnace wall comprising front and rear wall sections with an airspace between them, said front section including rows of blocks, meanssupporting said blocks for removal from the wall at the fire side of thewall without disturbing said rear wall section, and refractory facingbricks hooked on said blocks and removable from said blocks at the fireside of the wall while leaving said blocks in their normal positions inthe wall, said front wall section having air passages therein forcirculating air in contact with the rearward surfaces of said facingbricks.

21. A furnace wall comprising a permanent rear wall section, astructural steel frame in said wall including posts located in anintermediate position in the wall, a renewable lining located in frontof and spaced from said rear wall section and supported in its operativeposition by said frame, said lining comprising a plurality of rows ofrefractory blocks positioned one above another, said posts carrying thegreater part of the weight of said lining and being protected by saidblocks from the heat generated in the combustion chamber, and meansadditional to said blocks for protecting said posts from the heat insaid combustion chamber.

22. A furnace wall comprising front and rear wall sections, a structuralsteel frame in said wall for supporting said sections, said front sec-.tion including horizontal rows of refractory blocks arranged one aboveanother, and means carried by said frame for supporting said blocks intheir operative positions with said blocks disengageable from their saidsupporting means and removable from the wall at the fire side thereofwithout disturbing said rear wall section, said front section beingprovided with internal air passages connected with a supply of air forcirculating air through said front section but substantially confiningsaid circulation to regions behind the front face of the wall.

23. A furnace wall comprising front and rear wall sections, a structuralsteel frame in said wall for supporting said sections, said frontsection including horizontal rows of refractory blocks arranged oneabove another, and means carried by said frame for supporting saidblocks in their operative positions with said blocks disengageable fromtheir said supporting means and removable from the wall at the fire sidethereof without disturbing said rear wall section, said blocks in thefront section having renewable front face portions of such dimensionsthat a clearance will be provided both laterally and vertically betweenadjacent edges of said face portions when said blocks are in theirnormal positions in the wall.

24. A furnace wall comprising front and rear wall sections, a structuralsteel frame in said wall for supporting said sections, said frontsection including horizontal rows of refractory blocks arranged oneabove another, means carried by said frame for supporting said blocks intheir operative positions with said blocks disengageable from their saidsupporting means and removable from the wall at the fire side thereofwithout disturbing said rear wall section, said blocks in the frontsection including renewable front face portions composed of refractorymaterial having a different co-eflicient of expansion from that of therear sections of said blocks, said front face portions and the rearsections of said blocks being so proportioned that when said blocks arepositioned in a wall a clearance will be provided between the adjacentedges of said face portions to allow for expansion, and said front faceportions being free to expand and contract independently of the rearsections of said blocks.

OSCAR NYGAARD.

